Ad-hoc networks are an emerging technology with immense potential. Providing support for large-scale service and application deployment in these networks, however is crucial to make them a viable alternative. The lack of infrastructure, coupled with the time-varying characteristics of ad-hoc networks, brings about new challenges to the design and deployment of applications on a large-scale. This paper addresses these challenges and presents PeerNet, a unified, overlay-based service architecture to support large-scale service and application deployment in MANETs. We discuss the main functionalities of PeerNet, describe the algorithms for resource registration and discovery, and present PILOT, a novel power-aware, location-driven traffic forwarding algorithm to enable node interaction. We conclude the paper by comparing PILOT to LAR and AODV for a network of mobile nodes.